Campbell Scientific CR200/CR200X-series Dataloggers - Manual (Page 18)

Section 2. Quickstart Tutorial
2.1.7 Analog Sensors
Analog sensors output continuous voltages that vary with the phenomena
measured.
Analog sensors connect to analog terminals. Analog terminals are configured as
single-ended, wherein sensor outputs are measured with respect to ground
( FIGURE. Analog Sensor Wired to Single-Ended Channel #1 (p. 6)). The
CR200(X) cannot perform differential voltage measurements.
Figure 3: Analog Sensor Wired to Single-Ended Channel #1
2.1.8 Bridge Sensors
Bridge sensors change resistance with respect to environmental change.
Resistance is determined by measuring the difference between the excitation
voltage supplied to the bridge and the voltage detected by the CR200(X)
returning from the bridge.
2.1.8.1 Voltage Excitation
The CR200(X) supplies a precise excitation voltage via excitation terminals.
Return voltage is measured on single ended analog terminals. Because the
CR200(X) cannot make the differential voltage readings used with full bridge
and some half bridge circuits, only basic half bridge measurements can be made.
A wiring example is illustrated in FIGURE. Half Bridge Wiring Wind Vane
Potentiometer p. 7.
6